xref: /haiku/src/libs/compat/freebsd_wlan/net80211/ieee80211_tdma.c (revision 3c6e2dd68577c34d93e17f19711f6245bf6d0915)
1 /*-
2  * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
3  * Copyright (c) 2007-2009 Intel Corporation
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 #ifdef __FreeBSD__
29 __FBSDID("$FreeBSD$");
30 #endif
31 
32 /*
33  * IEEE 802.11 TDMA mode support.
34  */
35 #include "opt_inet.h"
36 #include "opt_tdma.h"
37 #include "opt_wlan.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/mbuf.h>
42 #include <sys/malloc.h>
43 #include <sys/kernel.h>
44 
45 #include <sys/socket.h>
46 #include <sys/sockio.h>
47 #include <sys/endian.h>
48 #include <sys/errno.h>
49 #include <sys/proc.h>
50 #include <sys/sysctl.h>
51 
52 #include <net/if.h>
53 #include <net/if_media.h>
54 #include <net/if_llc.h>
55 #include <net/ethernet.h>
56 
57 #include <net/bpf.h>
58 
59 #include <net80211/ieee80211_var.h>
60 #include <net80211/ieee80211_tdma.h>
61 #include <net80211/ieee80211_input.h>
62 
63 #ifndef TDMA_SLOTLEN_DEFAULT
64 #define	TDMA_SLOTLEN_DEFAULT	10*1000		/* 10ms */
65 #endif
66 #ifndef TDMA_SLOTCNT_DEFAULT
67 #define	TDMA_SLOTCNT_DEFAULT	2		/* 2x (pt-to-pt) */
68 #endif
69 #ifndef TDMA_BINTVAL_DEFAULT
70 #define	TDMA_BINTVAL_DEFAULT	5		/* 5x ~= 100TU beacon intvl */
71 #endif
72 #ifndef TDMA_TXRATE_11B_DEFAULT
73 #define	TDMA_TXRATE_11B_DEFAULT	2*11
74 #endif
75 #ifndef TDMA_TXRATE_11G_DEFAULT
76 #define	TDMA_TXRATE_11G_DEFAULT	2*24
77 #endif
78 #ifndef TDMA_TXRATE_11A_DEFAULT
79 #define	TDMA_TXRATE_11A_DEFAULT	2*24
80 #endif
81 #ifndef TDMA_TXRATE_TURBO_DEFAULT
82 #define	TDMA_TXRATE_TURBO_DEFAULT	2*24
83 #endif
84 #ifndef TDMA_TXRATE_HALF_DEFAULT
85 #define	TDMA_TXRATE_HALF_DEFAULT	2*12
86 #endif
87 #ifndef TDMA_TXRATE_QUARTER_DEFAULT
88 #define	TDMA_TXRATE_QUARTER_DEFAULT	2*6
89 #endif
90 #ifndef TDMA_TXRATE_11NA_DEFAULT
91 #define	TDMA_TXRATE_11NA_DEFAULT	(4 | IEEE80211_RATE_MCS)
92 #endif
93 #ifndef TDMA_TXRATE_11NG_DEFAULT
94 #define	TDMA_TXRATE_11NG_DEFAULT	(4 | IEEE80211_RATE_MCS)
95 #endif
96 
97 #define	TDMA_VERSION_VALID(_version) \
98 	(TDMA_VERSION_V2 <= (_version) && (_version) <= TDMA_VERSION)
99 #define	TDMA_SLOTCNT_VALID(_slotcnt) \
100 	(2 <= (_slotcnt) && (_slotcnt) <= TDMA_MAXSLOTS)
101 /* XXX magic constants */
102 #define	TDMA_SLOTLEN_VALID(_slotlen) \
103 	(2*100 <= (_slotlen) && (unsigned)(_slotlen) <= 0xfffff)
104 /* XXX probably should set a max */
105 #define	TDMA_BINTVAL_VALID(_bintval)	(1 <= (_bintval))
106 
107 /*
108  * This code is not prepared to handle more than 2 slots.
109  */
110 CTASSERT(TDMA_MAXSLOTS == 2);
111 
112 static void tdma_vdetach(struct ieee80211vap *vap);
113 static int tdma_newstate(struct ieee80211vap *, enum ieee80211_state, int);
114 static void tdma_beacon_miss(struct ieee80211vap *vap);
115 static void tdma_recv_mgmt(struct ieee80211_node *, struct mbuf *,
116 	int subtype, int rssi, int nf);
117 static int tdma_update(struct ieee80211vap *vap,
118 	const struct ieee80211_tdma_param *tdma, struct ieee80211_node *ni,
119 	int pickslot);
120 static int tdma_process_params(struct ieee80211_node *ni,
121 	const u_int8_t *ie, int rssi, int nf, const struct ieee80211_frame *wh);
122 
123 static void
124 settxparms(struct ieee80211vap *vap, enum ieee80211_phymode mode, int rate)
125 {
126 	vap->iv_txparms[mode].ucastrate = rate;
127 	vap->iv_txparms[mode].mcastrate = rate;
128 }
129 
130 static void
131 setackpolicy(struct ieee80211com *ic, int noack)
132 {
133 	struct ieee80211_wme_state *wme = &ic->ic_wme;
134 	int ac;
135 
136 	for (ac = 0; ac < WME_NUM_AC; ac++) {
137 		wme->wme_chanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
138 		wme->wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
139 	}
140 }
141 
142 void
143 ieee80211_tdma_vattach(struct ieee80211vap *vap)
144 {
145 	struct ieee80211_tdma_state *ts;
146 
147 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
148 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
149 
150 	ts = (struct ieee80211_tdma_state *) malloc(
151 	     sizeof(struct ieee80211_tdma_state), M_80211_VAP, M_NOWAIT | M_ZERO);
152 	if (ts == NULL) {
153 		printf("%s: cannot allocate TDMA state block\n", __func__);
154 		/* NB: fall back to adhdemo mode */
155 		vap->iv_caps &= ~IEEE80211_C_TDMA;
156 		return;
157 	}
158 	/* NB: default configuration is passive so no beacons */
159 	ts->tdma_version = TDMA_VERSION;
160 	ts->tdma_slotlen = TDMA_SLOTLEN_DEFAULT;
161 	ts->tdma_slotcnt = TDMA_SLOTCNT_DEFAULT;
162 	ts->tdma_bintval = TDMA_BINTVAL_DEFAULT;
163 	ts->tdma_slot = 1;			/* passive operation */
164 
165 	/* setup default fixed rates */
166 	settxparms(vap, IEEE80211_MODE_11A, TDMA_TXRATE_11A_DEFAULT);
167 	settxparms(vap, IEEE80211_MODE_11B, TDMA_TXRATE_11B_DEFAULT);
168 	settxparms(vap, IEEE80211_MODE_11G, TDMA_TXRATE_11G_DEFAULT);
169 	settxparms(vap, IEEE80211_MODE_TURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
170 	settxparms(vap, IEEE80211_MODE_TURBO_G, TDMA_TXRATE_TURBO_DEFAULT);
171 	settxparms(vap, IEEE80211_MODE_STURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
172 	settxparms(vap, IEEE80211_MODE_11NA, TDMA_TXRATE_11NA_DEFAULT);
173 	settxparms(vap, IEEE80211_MODE_11NG, TDMA_TXRATE_11NG_DEFAULT);
174 	settxparms(vap, IEEE80211_MODE_HALF, TDMA_TXRATE_HALF_DEFAULT);
175 	settxparms(vap, IEEE80211_MODE_QUARTER, TDMA_TXRATE_QUARTER_DEFAULT);
176 
177 	setackpolicy(vap->iv_ic, 1);	/* disable ACK's */
178 
179 	ts->tdma_opdetach = vap->iv_opdetach;
180 	vap->iv_opdetach = tdma_vdetach;
181 	ts->tdma_newstate = vap->iv_newstate;
182 	vap->iv_newstate = tdma_newstate;
183 	vap->iv_bmiss = tdma_beacon_miss;
184 	ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
185 	vap->iv_recv_mgmt = tdma_recv_mgmt;
186 
187 	vap->iv_tdma = ts;
188 }
189 
190 static void
191 tdma_vdetach(struct ieee80211vap *vap)
192 {
193 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
194 
195 	if (ts == NULL) {
196 		/* NB: should not have touched any ic state */
197 		return;
198 	}
199 	ts->tdma_opdetach(vap);
200 	free(vap->iv_tdma, M_80211_VAP);
201 	vap->iv_tdma = NULL;
202 
203 	setackpolicy(vap->iv_ic, 0);	/* enable ACK's */
204 }
205 
206 static void
207 sta_leave(void *arg, struct ieee80211_node *ni)
208 {
209 	struct ieee80211vap *vap = arg;
210 
211 	if (ni->ni_vap == vap && ni != vap->iv_bss)
212 		ieee80211_node_leave(ni);
213 }
214 
215 /*
216  * TDMA state machine handler.
217  */
218 static int
219 tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
220 {
221 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
222 	struct ieee80211com *ic = vap->iv_ic;
223 	enum ieee80211_state ostate;
224 	int status;
225 
226 	IEEE80211_LOCK_ASSERT(ic);
227 
228 	ostate = vap->iv_state;
229 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
230 	    __func__, ieee80211_state_name[ostate],
231 	    ieee80211_state_name[nstate], arg);
232 
233 	if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
234 		callout_stop(&vap->iv_swbmiss);
235 	if (nstate == IEEE80211_S_SCAN &&
236 	    (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
237 	    ts->tdma_slot != 0) {
238 		/*
239 		 * Override adhoc behaviour when operating as a slave;
240 		 * we need to scan even if the channel is locked.
241 		 */
242 		vap->iv_state = nstate;			/* state transition */
243 		ieee80211_cancel_scan(vap);		/* background scan */
244 		if (ostate == IEEE80211_S_RUN) {
245 			/* purge station table; entries are stale */
246 			ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
247 		}
248 		if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
249 			ieee80211_check_scan(vap,
250 			    vap->iv_scanreq_flags,
251 			    vap->iv_scanreq_duration,
252 			    vap->iv_scanreq_mindwell,
253 			    vap->iv_scanreq_maxdwell,
254 			    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
255 			vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
256 		} else
257 			ieee80211_check_scan_current(vap);
258 		status = 0;
259 	} else {
260 		status = ts->tdma_newstate(vap, nstate, arg);
261 	}
262 	if (status == 0 &&
263 	    nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
264 	    (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
265 	    ts->tdma_slot != 0 &&
266 	    vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
267 		/*
268 		 * Start s/w beacon miss timer for slave devices w/o
269 		 * hardware support.  Note we do this only if we're
270 		 * not locked to a channel (i.e. roam to follow the
271 		 * master). The 2x is a fudge for our doing this in
272 		 * software.
273 		 */
274 		vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
275 		    2 * vap->iv_bmissthreshold * ts->tdma_bintval *
276 		    ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
277 		vap->iv_swbmiss_count = 0;
278 		callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
279 			ieee80211_swbmiss, vap);
280 	}
281 	return status;
282 }
283 
284 static void
285 tdma_beacon_miss(struct ieee80211vap *vap)
286 {
287 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
288 
289 	KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
290 	KASSERT(vap->iv_state == IEEE80211_S_RUN,
291 	    ("wrong state %d", vap->iv_state));
292 
293 	IEEE80211_DPRINTF(vap,
294 		IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
295 		"beacon miss, mode %u state %s\n",
296 		vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
297 
298 	if (ts->tdma_peer != NULL) {	/* XXX? can this be null? */
299 		ieee80211_notify_node_leave(vap->iv_bss);
300 		ts->tdma_peer = NULL;
301 		/*
302 		 * Treat beacon miss like an associate failure wrt the
303 		 * scan policy; this forces the entry in the scan cache
304 		 * to be ignored after several tries.
305 		 */
306 		ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
307 		    IEEE80211_STATUS_TIMEOUT);
308 	}
309 #if 0
310 	ts->tdma_inuse = 0;		/* clear slot usage */
311 #endif
312 	ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
313 }
314 
315 static void
316 tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
317 	int subtype, int rssi, int nf)
318 {
319 	struct ieee80211com *ic = ni->ni_ic;
320 	struct ieee80211vap *vap = ni->ni_vap;
321 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
322 
323 	if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
324 	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
325 		struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
326 		struct ieee80211_scanparams scan;
327 
328 		if (ieee80211_parse_beacon(ni, m0, &scan) != 0)
329 			return;
330 		if (scan.tdma == NULL) {
331 			/*
332 			 * TDMA stations must beacon a TDMA ie; ignore
333 			 * any other station.
334 			 * XXX detect overlapping bss and change channel
335 			 */
336 			IEEE80211_DISCARD(vap,
337 			    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
338 			    wh, ieee80211_mgt_subtype_name[subtype >>
339 				IEEE80211_FC0_SUBTYPE_SHIFT],
340 			    "%s", "no TDMA ie");
341 			vap->iv_stats.is_rx_mgtdiscard++;
342 			return;
343 		}
344 		if (ni == vap->iv_bss &&
345 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
346 			/*
347 			 * Fake up a node for this newly
348 			 * discovered member of the IBSS.
349 			 */
350 			ni = ieee80211_add_neighbor(vap, wh, &scan);
351 			if (ni == NULL) {
352 				/* NB: stat kept for alloc failure */
353 				return;
354 			}
355 		}
356 		/*
357 		 * Check for state updates.
358 		 */
359 		if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
360 			/*
361 			 * Count frame now that we know it's to be processed.
362 			 */
363 			vap->iv_stats.is_rx_beacon++;
364 			IEEE80211_NODE_STAT(ni, rx_beacons);
365 			/*
366 			 * Record tsf of last beacon.  NB: this must be
367 			 * done before calling tdma_process_params
368 			 * as deeper routines reference it.
369 			 */
370 			memcpy(&ni->ni_tstamp.data, scan.tstamp,
371 				sizeof(ni->ni_tstamp.data));
372 			/*
373 			 * Count beacon frame for s/w bmiss handling.
374 			 */
375 			vap->iv_swbmiss_count++;
376 			/*
377 			 * Process tdma ie.  The contents are used to sync
378 			 * the slot timing, reconfigure the bss, etc.
379 			 */
380 			(void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
381 			return;
382 		}
383 		/*
384 		 * NB: defer remaining work to the adhoc code; this causes
385 		 *     2x parsing of the frame but should happen infrequently
386 		 */
387 	}
388 	ts->tdma_recv_mgmt(ni, m0, subtype, rssi, nf);
389 }
390 
391 /*
392  * Update TDMA state on receipt of a beacon frame with
393  * a TDMA information element.  The sender's identity
394  * is provided so we can track who our peer is.  If pickslot
395  * is non-zero we scan the slot allocation state in the ie
396  * to locate a free slot for our use.
397  */
398 static int
399 tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
400 	struct ieee80211_node *ni, int pickslot)
401 {
402 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
403 	int slot, slotlen, update;
404 
405 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
406 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
407 
408 	update = 0;
409 	if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
410 		if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
411 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
412 				printf("%s: bad slot cnt %u\n",
413 				    __func__, tdma->tdma_slotcnt);
414 			return 0;
415 		}
416 		update |= TDMA_UPDATE_SLOTCNT;
417  	}
418 	slotlen = le16toh(tdma->tdma_slotlen) * 100;
419 	if (slotlen != ts->tdma_slotlen) {
420 		if (!TDMA_SLOTLEN_VALID(slotlen)) {
421 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
422 				printf("%s: bad slot len %u\n",
423 				    __func__, slotlen);
424 			return 0;
425 		}
426 		update |= TDMA_UPDATE_SLOTLEN;
427  	}
428 	if (tdma->tdma_bintval != ts->tdma_bintval) {
429 		if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
430 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
431 				printf("%s: bad beacon interval %u\n",
432 				    __func__, tdma->tdma_bintval);
433 			return 0;
434 		}
435 		update |= TDMA_UPDATE_BINTVAL;
436  	}
437 	slot = ts->tdma_slot;
438 	if (pickslot) {
439 		/*
440 		 * Pick unoccupied slot.  Note we never choose slot 0.
441 		 */
442 		for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
443 			if (isclr(tdma->tdma_inuse, slot))
444 				break;
445 		if (slot <= 0) {
446 			printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
447 				__func__, tdma->tdma_slotcnt,
448 				tdma->tdma_inuse[0]);
449 			/* XXX need to do something better */
450 			return 0;
451 		}
452 		if (slot != ts->tdma_slot)
453 			update |= TDMA_UPDATE_SLOT;
454 	}
455 	if (ni != ts->tdma_peer) {
456 		/* update everything */
457 		update = TDMA_UPDATE_SLOT
458 		       | TDMA_UPDATE_SLOTCNT
459 		       | TDMA_UPDATE_SLOTLEN
460 		       | TDMA_UPDATE_BINTVAL;
461 	}
462 
463 	if (update) {
464 		/*
465 		 * New/changed parameters; update runtime state.
466 		 */
467 		/* XXX overwrites user parameters */
468 		if (update & TDMA_UPDATE_SLOTCNT)
469 			ts->tdma_slotcnt = tdma->tdma_slotcnt;
470 		if (update & TDMA_UPDATE_SLOTLEN)
471 			ts->tdma_slotlen = slotlen;
472 		if (update & TDMA_UPDATE_SLOT)
473 			ts->tdma_slot = slot;
474 		if (update & TDMA_UPDATE_BINTVAL)
475 			ts->tdma_bintval = tdma->tdma_bintval;
476 		/* mark beacon to be updated before next xmit */
477 		ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
478 
479 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
480 		    "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
481 		    __func__, ts->tdma_slot, ts->tdma_slotcnt,
482 		    ts->tdma_slotlen, ts->tdma_bintval);
483 	}
484 	/*
485 	 * Notify driver.  Note we can be called before
486 	 * entering RUN state if we scanned and are
487 	 * joining an existing bss.  In that case do not
488 	 * call the driver because not all necessary state
489 	 * has been setup.  The next beacon will dtrt.
490 	 */
491 	if (vap->iv_state == IEEE80211_S_RUN)
492 		vap->iv_ic->ic_tdma_update(ni, tdma, update);
493 	/*
494 	 * Dispatch join event on first beacon from new master.
495 	 */
496 	if (ts->tdma_peer != ni) {
497 		if (ts->tdma_peer != NULL)
498 			ieee80211_notify_node_leave(vap->iv_bss);
499 		ieee80211_notify_node_join(ni, 1);
500 		/* NB: no reference, we just use the address */
501 		ts->tdma_peer = ni;
502 	}
503 	return 1;
504 }
505 
506 /*
507  * Process received TDMA parameters.
508  */
509 static int
510 tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
511 	int rssi, int nf, const struct ieee80211_frame *wh)
512 {
513 	struct ieee80211vap *vap = ni->ni_vap;
514 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
515 	const struct ieee80211_tdma_param *tdma =
516 		(const struct ieee80211_tdma_param *) ie;
517 	u_int len = ie[1];
518 
519 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
520 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
521 
522 	if (len < sizeof(*tdma) - 2) {
523 		IEEE80211_DISCARD_IE(vap,
524 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
525 		    wh, "tdma", "too short, len %u", len);
526 		return IEEE80211_REASON_IE_INVALID;
527 	}
528 	if (tdma->tdma_version != ts->tdma_version) {
529 		IEEE80211_DISCARD_IE(vap,
530 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
531 		    wh, "tdma", "bad version %u (ours %u)",
532 		    tdma->tdma_version, ts->tdma_version);
533 		return IEEE80211_REASON_IE_INVALID;
534 	}
535  	/*
536 	 * NB: ideally we'd check against tdma_slotcnt, but that
537 	 * would require extra effort so do this easy check that
538 	 * covers the work below; more stringent checks are done
539 	 * before we make more extensive use of the ie contents.
540 	 */
541 	if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
542 		IEEE80211_DISCARD_IE(vap,
543 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
544 		    wh, "tdma", "invalid slot %u", tdma->tdma_slot);
545 		return IEEE80211_REASON_IE_INVALID;
546 	}
547 	/*
548 	 * Can reach here while scanning, update
549 	 * operational state only in RUN state.
550 	 */
551 	if (vap->iv_state == IEEE80211_S_RUN) {
552 		if (tdma->tdma_slot != ts->tdma_slot &&
553 		    isclr(ts->tdma_inuse, tdma->tdma_slot)) {
554 			IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
555 			    "discovered in slot %u", tdma->tdma_slot);
556 			setbit(ts->tdma_inuse, tdma->tdma_slot);
557 			/* XXX dispatch event only when operating as master */
558 			if (ts->tdma_slot == 0)
559 				ieee80211_notify_node_join(ni, 1);
560 		}
561 		setbit(ts->tdma_active, tdma->tdma_slot);
562 		if (tdma->tdma_slot == ts->tdma_slot-1) {
563 			/*
564 			 * Slave tsf synchronization to station
565 			 * just before us in the schedule. The driver
566 			 * is responsible for copying the timestamp
567 			 * of the received beacon into our beacon
568 			 * frame so the sender can calculate round
569 			 * trip time.  We cannot do that here because
570 			 * we don't know how to update our beacon frame.
571 			 */
572 			(void) tdma_update(vap, tdma, ni, 0);
573 			/* XXX reschedule swbmiss timer on parameter change */
574 		} else if (tdma->tdma_slot == ts->tdma_slot+1) {
575 			uint64_t tstamp;
576 #if 0
577 			uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
578 			int32_t rtt;
579 #endif
580 			/*
581 			 * Use returned timstamp to calculate the
582 			 * roundtrip time.
583 			 */
584 			memcpy(&tstamp, tdma->tdma_tstamp, 8);
585 #if 0
586 			/* XXX use only 15 bits of rstamp */
587 			rtt = rstamp - (le64toh(tstamp) & 0x7fff);
588 			if (rtt < 0)
589 				rtt += 0x7fff;
590 			/* XXX hack to quiet normal use */
591 			IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
592 			    "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
593 			    rtt, rstamp,
594 			    (unsigned long long) le64toh(tstamp));
595 #endif
596 		} else if (tdma->tdma_slot == ts->tdma_slot &&
597 		    le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
598 			/*
599 			 * Station using the same slot as us and has
600 			 * been around longer than us; we must move.
601 			 * Note this can happen if stations do not
602 			 * see each other while scanning.
603 			 */
604 			IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
605 			    "slot %u collision rxtsf %llu tsf %llu\n",
606 			    tdma->tdma_slot,
607 			    (unsigned long long) le64toh(ni->ni_tstamp.tsf),
608 			    vap->iv_bss->ni_tstamp.tsf);
609 			setbit(ts->tdma_inuse, tdma->tdma_slot);
610 
611 			(void) tdma_update(vap, tdma, ni, 1);
612 		}
613 	}
614 	return 0;
615 }
616 
617 int
618 ieee80211_tdma_getslot(struct ieee80211vap *vap)
619 {
620 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
621 
622 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
623 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
624 	return ts->tdma_slot;
625 }
626 
627 /*
628  * Parse a TDMA ie on station join and use it to setup node state.
629  */
630 void
631 ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
632 {
633 	struct ieee80211vap *vap = ni->ni_vap;
634 
635 	if (vap->iv_caps & IEEE80211_C_TDMA) {
636 		const struct ieee80211_tdma_param *tdma =
637 		    (const struct ieee80211_tdma_param *)ie;
638 		struct ieee80211_tdma_state *ts = vap->iv_tdma;
639 		/*
640 		 * Adopt TDMA configuration when joining an
641 		 * existing network.
642 		 */
643 		setbit(ts->tdma_inuse, tdma->tdma_slot);
644 		(void) tdma_update(vap, tdma, ni, 1);
645 		/*
646 		 * Propagate capabilities based on the local
647 		 * configuration and the remote station's advertised
648 		 * capabilities. In particular this permits us to
649 		 * enable use of QoS to disable ACK's.
650 		 */
651 		if ((vap->iv_flags & IEEE80211_F_WME) &&
652 		    ni->ni_ies.wme_ie != NULL)
653 			ni->ni_flags |= IEEE80211_NODE_QOS;
654 	}
655 }
656 
657 #define	TDMA_OUI_BYTES		0x00, 0x03, 0x7f
658 /*
659  * Add a TDMA parameters element to a frame.
660  */
661 uint8_t *
662 ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
663 {
664 #define	ADDSHORT(frm, v) do {			\
665 	frm[0] = (v) & 0xff;			\
666 	frm[1] = (v) >> 8;			\
667 	frm += 2;				\
668 } while (0)
669 	static const struct ieee80211_tdma_param param = {
670 		.tdma_id	= IEEE80211_ELEMID_VENDOR,
671 		.tdma_len	= sizeof(struct ieee80211_tdma_param) - 2,
672 		.tdma_oui	= { TDMA_OUI_BYTES },
673 		.tdma_type	= TDMA_OUI_TYPE,
674 		.tdma_subtype	= TDMA_SUBTYPE_PARAM,
675 		.tdma_version	= TDMA_VERSION,
676 	};
677 	const struct ieee80211_tdma_state *ts = vap->iv_tdma;
678 	uint16_t slotlen;
679 
680 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
681 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
682 
683 	memcpy(frm, &param, sizeof(param));
684 	frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
685 	*frm++ = ts->tdma_slot;
686 	*frm++ = ts->tdma_slotcnt;
687 	/* NB: convert units to fit in 16-bits */
688 	slotlen = ts->tdma_slotlen / 100;	/* 100us units */
689 	ADDSHORT(frm, slotlen);
690 	*frm++ = ts->tdma_bintval;
691 	*frm++ = ts->tdma_inuse[0];
692 	frm += 10;				/* pad+timestamp */
693 	return frm;
694 #undef ADDSHORT
695 }
696 #undef TDMA_OUI_BYTES
697 
698 /*
699  * Update TDMA state at TBTT.
700  */
701 void
702 ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
703 	struct ieee80211_beacon_offsets *bo)
704 {
705 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
706 
707 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
708 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
709 
710 	if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
711 		(void) ieee80211_add_tdma(bo->bo_tdma, vap);
712 		clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
713 	}
714 	if (ts->tdma_slot != 0)		/* only on master */
715 		return;
716 	if (ts->tdma_count <= 0) {
717 		/*
718 		 * Time to update the mask of active/inuse stations.
719 		 * We track stations that we've received a beacon
720 		 * frame from and update this mask periodically.
721 		 * This allows us to miss a few beacons before marking
722 		 * a slot free for re-use.
723 		 */
724 		ts->tdma_inuse[0] = ts->tdma_active[0];
725 		ts->tdma_active[0] = 0x01;
726 		/* update next time 'round */
727 		/* XXX use notify framework */
728 		setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
729 		/* NB: use s/w beacon miss threshold; may be too high */
730 		ts->tdma_count = vap->iv_bmissthreshold-1;
731 	} else
732 		ts->tdma_count--;
733 }
734 
735 static int
736 tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
737 {
738 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
739 
740 	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
741 		return EOPNOTSUPP;
742 
743 	switch (ireq->i_type) {
744 	case IEEE80211_IOC_TDMA_SLOT:
745 		ireq->i_val = ts->tdma_slot;
746 		break;
747 	case IEEE80211_IOC_TDMA_SLOTCNT:
748 		ireq->i_val = ts->tdma_slotcnt;
749 		break;
750 	case IEEE80211_IOC_TDMA_SLOTLEN:
751 		ireq->i_val = ts->tdma_slotlen;
752 		break;
753 	case IEEE80211_IOC_TDMA_BINTERVAL:
754 		ireq->i_val = ts->tdma_bintval;
755 		break;
756 	default:
757 		return ENOSYS;
758 	}
759 	return 0;
760 }
761 IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
762 
763 static int
764 tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
765 {
766 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
767 
768 	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
769 		return EOPNOTSUPP;
770 
771 	switch (ireq->i_type) {
772 	case IEEE80211_IOC_TDMA_SLOT:
773 		if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
774 			return EINVAL;
775 		if (ireq->i_val != ts->tdma_slot) {
776 			ts->tdma_slot = ireq->i_val;
777 			goto restart;
778 		}
779 		break;
780 	case IEEE80211_IOC_TDMA_SLOTCNT:
781 		if (!TDMA_SLOTCNT_VALID(ireq->i_val))
782 			return EINVAL;
783 		if (ireq->i_val != ts->tdma_slotcnt) {
784 			ts->tdma_slotcnt = ireq->i_val;
785 			goto restart;
786 		}
787 		break;
788 	case IEEE80211_IOC_TDMA_SLOTLEN:
789 		/*
790 		 * XXX
791 		 * 150 insures at least 1/8 TU
792 		 * 0xfffff is the max duration for bursting
793 		 * (implict by way of 16-bit data type for i_val)
794 		 */
795 		if (!TDMA_SLOTLEN_VALID(ireq->i_val))
796 			return EINVAL;
797 		if (ireq->i_val != ts->tdma_slotlen) {
798 			ts->tdma_slotlen = ireq->i_val;
799 			goto restart;
800 		}
801 		break;
802 	case IEEE80211_IOC_TDMA_BINTERVAL:
803 		if (!TDMA_BINTVAL_VALID(ireq->i_val))
804 			return EINVAL;
805 		if (ireq->i_val != ts->tdma_bintval) {
806 			ts->tdma_bintval = ireq->i_val;
807 			goto restart;
808 		}
809 		break;
810 	default:
811 		return ENOSYS;
812 	}
813 	return 0;
814 restart:
815 	ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
816 	return ERESTART;
817 }
818 IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);
819